Compaction machines are frequently employed for compacting fresh laid asphalt, soil or other compactable materials. One such type of compaction machine is a drum-type compactor having one or more drums that compacts material over which the compactor is driven. In order to compact the material, these drum-type compactors include a drum assembly having a vibratory mechanism, which includes inner and outer eccentric weights arranged on a rotatable shaft or a key shaft. The key shaft is positioned within an inner cavity of the inner eccentric weight such that as the key shaft rotates, it causes the rotation of the inner and the outer eccentric weights to induce vibrations on the drum for compacting material.
In order to facilitate rotation of the inner and the outer eccentric weights, the key shaft is engaged to those weights by way of various splined structures provided on an outer surface thereof. For example, the outer surface of the key shaft may be provided with axial or straight splined portions that engage with the inner eccentric weight, as well as helical splined portions that engage with the outer eccentric weight to facilitate rotation of those eccentrics. Such continuous engagement, as well as rotation, of the key shaft, the inner and the outer eccentrics causes the splined portions of the key shaft to wear and tear over time. Such wear and tear not only reduces the performance of the key shaft and the inner and the outer eccentric weights to affect the performance of the compaction machine in compacting material, it also reduces the life span of the key shaft requiring frequent and typically expensive replacements.
To prevent and/or minimize wear and tear of the key shaft and, particularly, minimize the wear and tear of the splined portion of the key shaft, lubrication to the key shaft is provided. Generally, the lubrication system provided within the vibratory mechanism for lubricating the inner and the outer eccentric weights, as well as the components of the vibratory system is employed for lubricating the key shaft as well. Although such a system lubricates the key shaft, it only insufficiently lubricates the key shaft, still causing premature wear and tear thereof.
Accordingly, it would be beneficial if a system for sufficiently lubricating the key shaft were developed. It would additionally be beneficial if such a system did not affect the performance of the key shaft, prevented premature spline wear on the key shaft and provided lubrication to the key shaft in a cost effective manner without requiring frequent replacements.